It is important to rule out curable medical problems before investing in a hearing aid. Some hearing-aid dispensers often sell aids to individuals who don’t need them or would be better served by other treatments. The U.S. Food and Drug Administration (FDA) prohibits the sale of a hearing aid to anyone who does not present a written statement signed by a licensed physician saying that the patient’s hearing has been evaluated. A hearing-aid dispenser may lawfully sell an aid to someone who possesses no such statement only if the seller has informed the consumer that getting a medical examination is in the best interest of the consumer’s health and the consumer has signed a waiver of the right to a medical examination.

If the physician advises you to obtain a hearing test to determine the type and degree of your hearing loss, and whether you are a candidate for a hearing aid, an audiologist or a “hearing-aid specialist” can administer one.

Audiologists have extensive training and usually hold a clinical Doctor of Audiology (Au.D.) degree but may hold a Sc.D. or Ph.D. Audiologists may also be identified by the letters CCC-A (denoting a Certificate of Clinical Competence in Audiology from the American Speech-Language-Hearing Association) or FAAA (Fellow of the American Academy of Audiology). In addition to administering hearing tests, audiologists can provide complete diagnostic evaluations of hearing loss. After hearing tests, audiologists usually help patients select and purchase hearing aids.

Unlike audiologists, hearing-aid specialists are not required to have degrees in the field of hearing. You can see whether a hearing-aid specialist has voluntarily been certified by the National Board for Certification in Hearing Instrument Sciences, as indicated by the letters NBC-HIS. To receive certification, applicants must have two years of experience selling hearing aids and pass the National Competency Exam.

If you do get a hearing aid, have your hearing retested periodically to determine if adjustment might help. How often you have your hearing retested depends on the extent of your loss and other factors; most hearing-aid wearers should be retested at least every other year, but some may need to be retested every six months.